Oil cooler



May 17, 1949- l E. c. wARRlcK ETAL 2,470,667

OIL COOLER Filed Jan. 10, 1944 2 Sheets-'Sheet 1 iii O IQ 1 o o -o 9 o O 26 O oo vwe/row o 17 O Oo v Harold C'IUalb 77 O $5519 EdwafdCJ/Irrick.

May 17, 1949 E. c. wARRlcK ETAL 2,470,667

OIL COOLER Filed Jan. l0, 1944 2 Sheets-Sheet 2 o Harold Crugah,

:Qq Edward attenua,

Patented May 17,' 1949 on. cooLEa Edward C. Warrick, Cincinnati, Ohio, and Harold Cruzan, Los Angeles, Calif., assignors to United Aircraft Products, Inc., Dayton, Ohio, a corporation of Ohio Application January 10, 1944, Serial No. 517,720

9 Claims. l

This invention relates to a liquid cooling unit for use in a liquid circulatory system of the type through which a liquid of variable viscosity is circulated under pressure, and has for its general object to provide a liquid cooling unit including a heat exchange portion and novel means to cause the liquid, if it is at or above a certain condition of fluidity or viscosity to flow through said heat-exchange portion for cooling, and to by-pass said heat-exchange portion if it is at or below a certain condition of viscosity or congealation such. as might, under an abnormal pressure in the system, cause the cooling unit to be iniured or damaged.

Oneexample of a liquid circulatory system, in which is employed a unit for cooling the liquid circulated through the system, is the lubricant circulating system of an internal combustion engine used for powering aircraft. In a system of this type and under the normal operating conditions of the aircraft, cooling of the lubricant is required to maintain the same within a range of temperature and of viscosity for most efficient performance. At times, however, due to the engine of the aircraft remaining idle in a cold atmosphere, or to idling or stopping of the engine during a dive or other period-of operation of the aircraft, or to other causes, the lubricant con-` tained in the heat exchange portion of the cool- In that event, bursting of the cooling unit or other injury thereto might result from subjecting the congealed liquid to an abnormally high pressure such as might occur due to suddenly increasing the speed of the engine or to starting of the engine following a period of idlying thereof. Accordingly, under such conditions and in accordance with the instant invention, the lubricant in the system, exclusive of that portion thereof which may be contained in the he'at exchange portion of the cooling unit, is circulated through the system in by-passing relationship to the cooling unit.

It is, of course, desirable to re-establish flow of the lubricant through the heat exchange portion of the cooling unit as soon as possible after starting of the engine or upon resumption of normal operation thereof, following any given period of time when the lubricant contained in the heat exchange portion of the cooling unit may have become congealed to such an extent as to obstruct flow of the lub-ricant therethrough. Therefore, another important object of the invention is to provide a cooling unit embodying a novel con-a struction whereby that portion of the lubricant which is circulated through the system in bypassing relationship `to the heat exchange portion of the cooling unit, acts upon the congealed lubricant in the heat exchange portion of the cooling unit to quickly restore its fluidity and thus speedily to re-establish circulation of the lubricant through the 'heat exchange portion of the cooling unit upon starting of the eng-lne or upon resumption of normal operation thereof, following any given period of time during which the liquid in the heat-exchange portion of the cooling unit may have become congealed.

Another important object of the invention is to provide a cooling unit embodying the features mentioned and which is of simple, sturdy construction and of comparatively lowproduction cost, which may be manufactured with facility and expedition, and which is highly efficient in operation.

With the foregoing and other objects in view, ,which will become ,more fully apparent as the nature' of the invention is better'understood, the same resides in a cooling unit embodying the novel features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated in Ltheaccompanying drawings and defined in the appended claims.

In the accompanying drawings, Vwherein like characters of references denotecorresponding parts in the different views: Q

Figure 1 is a perspective view of a cooling unit constructed in accordance withone practical embodiment of the invention;

Figure 2 is a central, vertical, longitudinal section through the cooling unit; I

Figure 3 is a transverse section on the line 3 3 of Figure 2;

Figure 4 is'a transverse section on the line I-I of Figure 2; and

Figure 5 is a sectional view of the valve for controlling flow of liquid through the unit.

` Referring to the drawings in detail, it will be observed that the present cooling unit, according to thepractical embodiment thereof illustrated inthe present instance, comprises primarily a casing, designated as i0-, housing the heat-exchange portions of the unit; a manifold.' designated as II, secured to the top of said casing I l) exteriorly thereof; a valve housing, designated as I2, superimposed upon the manifold Il and cooperating therewith to provide passageways for n'flow of liquid to and from the casing I0 and in by-passing relationship thereto; and a valve, designated generally as I3, mounted in said housing tained in the casing IIJ.

3 I2 for controlling iiow of the liquid either through the casing I or in by-passing relationship thereto depending upon the viscosity of the liquid con- Preferably the casing I0 is cylindrical in form. It may, however, be of any desired configuration in cross section, and of any desired diameter and length. In any event, it is open at its ends and at its bottom is provided with a passageway I4 which extends substantially throughout the length thereof and which is in communication with a central duct section I5 of the manifold II by means of a series of open-ended vertical tubes I6 which are disposed in side-by-side spaced apart relationship in and along the central, Vertical, longitudinal plane of the casing. Moreover, a series of vertically spaced horizontally disposed plates I1 extend from side to side of the casing I0 and cooperate with each other and with the casing to provide a single and continuous passageway I8 extending progressively upwardly through the casing from the bottom to the top thereof and also progressively in opposite directions longitudinally from end to end thereof. Furthermore, all available space in the casing I8, and particularly in the passageway I8 to either side of the vertical series of tubes I6, is filled by a honeycomb assemblage of tubes I9 which are open at their ends and which extend longitudinally to the casing in parallel, slightly spaced relationship to each other .to divide the passageway I8 into a maze of narrower spaces surrounding said tubes I9, whereby liquid flowing through the casing is divided into small bodies for rapid cooling by air or any other cooling medium flowing through the tubes I9.

At their ends the tubes I9 may be of polygonal shape in cross section and also may be nested and soldered together to close the passageway I8 at the ends of the casing I0; or, alternatively, s aid passageway I8 may be closed at the ends of the casing in any other suitable manner. In any event, the passageway I8 is in communicating at its lower end with one end of the passageway I4 and at its upper end communicates with a duct section of the manifold Il that is separate and distinct from the duct section I5 thereof.

According to the construction illustrated in the drawings, the passageway I4 is formed in the bottom of the casing IIl by a horizontal plate 2| spaced a suitable distance above the bottom of the casing and extending from side to side thereof substantially throughout the length thereof, in combination with a pair of closure elements 22 at the ends of said plate between the same and the bottom of the casing. Also, according tothe construction illustrated in the drawings, the tubes I6 at their bottoms extend .through openings in the plate 2I and thereby are in communication with the passageway I4, and at their tops extend through openings in the top of the casing I0 and thereby are .in communication with the duct section I5 of the manifold II. Likewise, the passageway I8 is in the communication at its lower end with one end of the passageway I4 by means of an opening 23 in the plate 2|, and at its upper end is in communication with the duct section 20 of the manifold II by means of opening 24 in the top of the casing. Obviously, any equivalent construction may be employed, the specific construction illustrated and just described merely being representative or typical of a number or variety of constructions which may feasibly be employed from a practical and economical manufacturing standpoint.

In the top wall of the manifold I I are two openings 25 and 26, the former of which constitutes an outlet from the duct section I5 and the latter of which constitutes an outlet from the duct section 20 of the manifold, while in the bottom wall of the valve housing I2 are two other openings 21 and 28, which, in conjunction with the openings 25 and 26, respectively afford communication between the duct sections I5 and 20 of the manifold II and the interior of the valve housing I2 under the control of the aforementioned valve I3 and a check valve 29, the former of which is associated with the openings 25, 21 and the latter of which is associated with the openings 26, 28.

The valve I3 may be of any suitable type such that, during normal operation of the system of which the cooling unit is a part, it is yieldably/ biased toward closing relationship to the openings 25, 21 and is adapted to be opened by an abnormally high pressure of liquid in the duct section I5. On the other hand, the check valve 29 may be of any suitable type to permit flow of liquid through the openings 26 and 28 from the duct section 28 of the interior of the valve housing I2 and to deny flow of liquid from said valve housing I2 to said duct section 20.

The manifold II is suitably formed, as indicated at 38, to have connected therewith a conduit for delivering liquid to the duct I5, while the valve housing I2 is suitably formed, as indicated at 3|, to have connected therewith a conduit for conducting liquid therefrom.

The valve I3'is closed during normal operation of the system. Therefore, it will be apparent that normally the liquid will now into the duct section I5, downwardly through the tubes I6 into the passageway I4, from said passageway III through the openings 23 in the plate 2i into the lower end of the passage I8, upwardly through the maze of spaces in said passageway I8 between the tubes I9 therein, from the upper end of said passageway I8 through the openings 24 in the top of the casing I0 into the duct section 20 of the manifold lI, through the openings 26, 28 into the valve housing I2, and from said valve housing through the outlet conduit connected therewith.

As long as the liquid remains above a certain temperature and viscosity so that it flows through the heat exchange portion of the cooling unit it will be cooled due to extraction of heat therefrom by air or any other cooling medium flowing through the tubes I9. However, should the liquid in the heat exchange portion of the cooling unit, for any reason, become congealed to an extent to obstruct its flow through said heat exchange portion, pressure in the system thereupon will rise and the valve I3 will be forced open, thus permitting the liquid to ow from the duct section I 5 through the openings 25, 21 into the housing I2 in by-passing relationship to the heat exchange portion of the cooling unit. Thus, any harm to the cooling unit in consequence of the liquid becoming congealed in the heat exchange portion thereof is effectively avoided.

The tubes I6 arerprovided along their lengths with small holes 32 through which small quantities of liquid may flow from said tubes into the passageway I8. However, the amount of liquid which may escape from the tubes I6 through the holes 32 is only a small fraction of the totalvolume of liquid which iiows through said tubes during normal operation of the cooling unit. The

fact that it fails to flow completely through the cooling unit due to its short path of travel depending upon the location of the holes 32, is of little or no consequence so far as concerns the emciency of the unit. In any event, when the liquid in the heat exchange portion of the cooling unit is congealed, the higher temperature liquid being circulated through the system in by-passing relationship to the heat-exchange portion of the cooling unit, acts progressively downwardly through the tubes I6. by heat conduction and pressure to raise the temperature of the .congealcd liquid in saidtubes, and to progressively free said tubes of congealed liquid. As the liquid in the tubes I6 is warmed it escapes through the holes 32into the passageway I8 and acts to warm and deccngeal the congealed liquid in said passageway, thereby -far more quickly restoring circulation through the heat exchange portion of `the cooling unit than would be the case if the holes 32 were not provided.` The number and arrangement or pattern of the openings 32 is determined in part by the size of such openings, as well as by the size and type of oil cooler and by the temperatures in'which the cooler is de- If there is ,no obstruction to'flow of lubricant through the heat-exchange portion of the cooling unit when the engine is started and the valve I3 is slightly open, the maior portion of the lubricant will now through the heat exchange portion of the unit and but a small portion o! theliquid will flow through the openings 25, 21 in by-passing relationship to the heat 'exchange portion until the thermal element 34l acts to completely close the valve I3, whereupon, all of the liquid will be caused to flow through the heatexchange 'portion of the unit. In this connection it will be observed that' there isl provided l in the housing; I2 a baule wall which serves to direct the lubricant, as it enters said housing throughv the openings 26, 28, toward the valve Il so that the heatfof the lubricant will act on thev thermal element 34 to maintain saidv valve closed.

f course,` when the heat-exchange portion of the unit is obstructed, the spring 33 will permit the assembly comprising the valve Il and thermal means 34 to rise a greater or lesser signedto operate. The pattern shown, in Fig. 2

is an example of the ,usually preferred arrangements. l

Upon restoration of aA condition of. uidity of the liquid in the heat exchange portion ofthe cooling unit so that it may ilowV lthrough the unit under the normal pressure in the system, the valve I3 closes and prevents by-passing of the heat exchange portion of the unit and at the same time requires the liquid to pass through the heat exchange portion'` of the cooling unitto be cooled therein.v y l,

Obviously, onlyoa single tube I6, or its equivalent, or any desiredv number of said tubes or their equivalents, may be lemployed `to conduct liquid -fromtthe duct -section I5 of the manifold II to the passageway I4. Obviously, too, any suitable heat exchange means, other than the means @specifically illustrated and described, may be employed' within vthe .casing I0 to eiect rapid Vcooling of the liquid owing through said casing. -Moreover, themanifold I'I and the valve tegrally with or separately from each other and either integrally with or separately from the casing I0. v

Preferably the valve I3 is of a type which includes a relief spring 33 and a thermal element 34 for urging the valve closed. Preferably, too, said valve vis arranged so thatit is closed when said thermal element is subjected to the heat oi" lubricant circulating through the system and remains slightly open when its thermal element 34 is not subjected to the heat of lubricant in the system. Thus, during any period of idleness of the engine during which the lubricant in the housing I2 cools, the valve I3 opens slightly and remains slightly open so that when the engine is `started there is immediate relief through the openings 25, 21 from' any surge or other pressure developed in the 'system as a result of starting of the engine, This is important in protecting the heat-exchange portion of the cooling unit from pressure surges when the engine is started after the lubricant in the system may have beamount for bil-Dass flow of the lubricant, dei pending upon the pressure of the liquid.

The check valve 29 not only prevent any backflow of lubricant through the heat exchange portion of the cooling unit, but serves to protect said portion of the unit against damaging pressure of the liquid when `the tubes' I6 are obstructed and thehlubricant is flowing into' the housing I2 through the openings 25, 21. f

Without further description it is believed `evi-` dent that the-construction, operation and advantages of a cooling unit. embodying the features of come cool, even though there is no obstruction t .change portion of the cooling@ unit from vany surging or other pressure developed in the systern, in the event the lubricant Vin said heatexchange portion may have become congealed.

-the invention will be clearly understood. It is desired to point out, however, that while only a single speciiic construction has been illustrated and described, the invention may readily be embodied in specifically different or various types of construction within its spirit and scope as defined in the appended claims.

What is claimed is:

1. A iiquid cooling unit for use in a. liquid circulating system, said unit comprising a casing, housing I2 manifestly may be formed either in- ..40

4the ow of liquid therebetween exteriorly, means for the supply of liquid to said conduits, means;

for the outlet of liquid from said casing at a point remote from said side thereof, means lfor causing liquid flowing through said casing between said conduits and said outlet means to flow substantially throughout that portion voi? the length of the' casing which is occupied by said series `of conduits, means for cooling the liquid during its flow through said casing, and means requiring the liquid normally to ow through said conduits andthe casing and to effect ilow of the liquid between said inlet and said outlet means in by-passing relationship to said conduits and said casing in response to obstruction to flow of the liquid through said conduits and said casing. Y

2. A liquid cooling unit for use in a liquid circulating system, said unit comprising a casing, a series of conduits extending transversely across said casing for supply of liquid thereto adjacent to one side thereof, said conduits being spaced apart longitudinaliy'aof the casing and in series extending throughout a major portion4 of the length of said casingland further being spaced through apart for the flow of liquid therebetween exteriv orly, means for the supply of liquid to said concasing between said conduits and said outlet means to flow substantially throughout that por- 'tion of the length of the casing which is occupied by said series of conduits, means for cooling the liquid during its flow through said casing, and means requiring .the liquid normally to flow through said conduits and the casing and to eiect flow of the liquid between said inlet and said outlet means in icy-passing relationship to said conduits and said casing in response to obstruction to flow of the liquid through said conduits and said casing, said conduits having passages therein spaced along the lengths thereof for delivery of predetermined quantities of liquid from the conduits directly into the casing.

3. A liquid cooling unit for use in a liquid circulating system, said unit comprising a casing, means at one side of said casing defining a passageway extending substantially throughout the length of the casing, means at the opposite side of said casing defining a liquid supply duct substantially co-extensive in length with said passageway, a series of tubes extending transversely across said casing and connecting said duct with said passageway at points spaced along the length thereof, said tubes being spaced apart for the iiow of liquid therebetween exteriorly, means defining a tortuous passageway extending through said casing successively in opposite directions substantially from end to end thereof and between said sides thereof, means providing communication between one end of said first-mentioned passageway and one end of said tortuous passageway, means providing a liquidv outlet from the casing in communication with the other end of said tortuous passageway?, means for cooling liquid ilowing through said tortuous passageway, and means requiring the liquid normally to iiow from the supply duct through said tubes and said tortuous'passageway to said outlet means and to cause the liquid to now between said supply duct and said outlet means in by-passing relationship to said tubes and said tortuous passageway in response to obstruction to flow of the liquid said tubes and said tortuous passageways.

4. A liquid cooling unit for use in a liquid circulating system, said unit comprising a casing, means at one side of said casing defining a passageway extending substantially throughout the length of the casing, means at the opposite side of said casing defining a liquid supply duct substantially co-extensive in length with said passageway, a series of tubes extending transversely across said casing and connecting said duct with said passageway at points spaced along the lengths thereof, said tubes being spaced apart for the flow of liquid therebetween exteriorly, meansl defining a Atortuous passageway extending through said casing successively in opposite directions substantially from end to end thereof and between said sides thereof, means providing communication between one end of said firstmentioned passageway and one end of said tortuous passageway, means providing a liquid outlet from the casing in communication with the other end of said tortuous passageway, means for cooling liquid flowing through said tortuous passageway, and means requiring the liquid normally to flow from the supply duct through said tubes and said passageways to said outlet means and to cause the liquid to now between said supply duct and said outlet means in by-passing relationship to said tubes and said passageways in response to obstruction to ilow of the liquid through the tubes and the passageways, said tubes having holes spaced along the lengths thereof for delivery of small quantities of liquid from said tubes directly into said tortuous passageway.

5. An oil temperature regulator of the jacketless type, comprising a casing; an inlet and outlet fitting mounted on said casing; a plurality of tube-like conduits disposed transversely of said casing, one of the ends of said conduits extending into said casing and the opposite ends thereof opening to the exterior of said casing in a position underlying said fitting, said conduits being spaced from each other for the flow of oil therebetween exteriorly and arranged in a longitudinal row; an inlet passage in said tting communicating with all of said conduits whereby the oil to be conditioned may enter said fitting and be discharged through said conduits into said casing; an outlet from the casing to said fitting; and a controlled by-pass in said iltting connecting said inlet passage and tting outlet.

6. An oil temperature regulator of the jacketless type, comprising a casing, an assembly of heat exchange tubes in said casing, arranged for the passage of a fluid therethrough as a coolant and for the passage therearound of oil to be cooled, a header chamber at one side of said casing and communicating with the interior thereof, a plurality of conduits extending from outside said casing and into said casing through said assembly of tubes to said header chamber, said conduits being spaced apart so that the oil may flow between them exteriorly, an outlet opening in said casing the oil flowing through said conduits to said header chamber and from said header chamber around tubes of said assembly of heat exchange tubes to said outlet, a fitting mounted on said casing in overlying relation to the outer ends of said conduits and said outlet, rst and second chambers in said fitting respectively communicating with said conduits and said outlet, means for admitting oil to be cooled to said rst chamber, a port interconnecting said first and second chambers in said fitting, and a tensioned valve controlling iiow through said port. f

7. An oil temperature regulator according to claim 6 characterized by operating means for said valve including a thermostat interposed in the path of oil flowing through said port and of oil flowing from said outlet.

8. An oil temperature regulator of the jacketless type, comprising a casing, means within said casing defining flow paths for the oil in heat exchange relation with a coolant, a header chamber at one side of said casing and communicating with the interior thereof, said casing having an opening representing the terminus of the flow paths within said casing, a plurality of conduits extending from' outside said casing into said casing to said header chamber, said conduits being spaced apart so that the oil may flow between them exteriorly, a fitting mounted on said casing in overlying relation to the outer ends of said conduits and to said opening in said casing, a first chamber in said fitting communicating withthe outer ends of said conduits, a second chamber in said fitting communicating with the opening in said casing, means for admitting oil to be cooled to said mst chamber, a controlled by-pass in said tting connecting said first and second chambers, and by-pass ports ln said conduits vfor the discharge of small quantities oi oil directly into the now paths within said casing and in by-passing relation to said header chamber. Y

9. An oil `temnei'ature regulator according t0 claim 8 characterized in that the controls for said controlled lay-pass in said fitting comprise a valve for controlling flow through said by-pass, a thermostat exposed to theI temperature of the oil flowing through said port and of the oil leaving the opening in said casing for actuating said valve, and a spring permitting said valve to move yieldingly to open position under pressure irrespective of the temperature of. the oil.

EDWARD C. WARRICK. HAROLD CRUZAN.

REFERENCES CITED The following references are of record in the le of this patent:

Number Number 20 460,047 593,062

' l0 UNITED STATES PATENTS.

Name Date Cole May 31, 1932 Young Feb. 26, 1935 Bailllo --.L July 9, 1935;-` BelaieiI Nov. 19, 1940 Ware Mar. 10, 1942 Worth Apr. 7, 1942 Ramsaur July 7, 1942 Kuhlmann Aug. 4, 1942 Ramsaur Jan. 5, 1943 Mormile June 15, 1943 Hoiman Mar. 14, 1944 Hannon Mar. 14, 1944 Garner July 4, 1944 Cruzan et al. Aug. 20, 1946 FOREIGN PATENTS Country Date Great Britain Jan. 20, 1937 France May 14, 1925 

